iBook - stuck in the macOS tiger installation process

I started installing from the cd set, and realized I only had the first 3 cds. Ive tried booting from the dvd on an external drive (my ibook does not have a dvd drive, sadly) and it won't recognize the dvd drve as a boot drive. My next idea is to either boot from the first cd and do a custom install excluding all the stuff on the last cd or break up the dvd into .imgs in order to make the fourth cd. any ideas?